TrackSec 4 Channel AHD 720P H.264 Mobile DVR Recorder with G-Sensor Car Black Box Kit - 4 Weatherproof Side View Cameras, 7 inch Car Monitor, Video Extension Cords and More AHD 720P (1280 x 720) high resolution recording. Video quality AHD 720P/D1 adjustable DC 10-36V Wide Voltage Input. Special design for all kinds of vehicles. Provide reverse voltage / overload / short circuit protection. Supports up to dual 128GB SD cards(NOT INCLUDED) storage. It can record max. 60 hours before overwriting the previous footages 4.4'' x 1.4'' x 5.4'' Small dimension saves your space. Vibration-proof, can work in harsh environment Acceleration/G-sensor record the vehicle's speed, gravitational changes to analyze out of ordinary events happen, for example, if the driver brakes suddenly or turns sharply.